7.1.1 SMR selection and assumptions for the estimates

The primary aim of the estimates of LUEC performed and presented in this chapter is to obtain an independent LUEC value for next-of-a-kind SMRs starting from a reliable evaluation of overnight capital cost, operation and maintenance (O&M) and fuel costs for some reference large reactors. The scaling law and the correction factors analysed in Chapter 6 have been used for this analysis (see Figure 7.1). The resulting evaluations were then compared to the designers’ cost data in 2009 USD given in Table 6.2. Such a comparison was found useful to understand the various factors influencing the economics of the SMRs, and also to highlight the points that would probably require further clarification.

Figure 7.1. Schematic description of the LUEC methodology applied

Capital costs for relevant NPPs with large reactors (USD per kWe)

Economy of Scale (scaling law): Cost(P1)=Cost(P0)(P1/P0)n P0,P1 — power, n — scaling law parameter

Other factors affecting the competitiveness of SMRs:

— Design simplification

— Shorter construction period

— FOAK effect and multiple units

— Factory fabrication, learning

Output of the calculation: Capital costs for SMRs (USD/kWe) Assumptions on the costs of O&M, fuel, and decomissioning

Estimates of LUEC (USD/MWh)

While using the approach mentioned above it should be kept in mind that the available economic data on nuclear power plants has a large degree of uncertainty which is, in particular, related to the implicit impact of the non-quantifiable factors.

Also, the algorithms of the scaling law and the correction factors described in Chapter 6 are necessarily approximate, include essential simplifications, and reflect only the experience of certain types of NPPs that have been built in the past. For those reasons, we made the following assumptions in the study:

• We consider only SMRs based on pressurised water reactor technology, which have the highest potential of being deployed within the current decade. Within this technology reasonably reliable data on the overnight capital costs, O&M and fuel costs are available for NPPs with large reactors recently deployed (or being constructed) in several countries.

• The evaluations were performed for some “model” SMRs denoted as PWR-X, (where X stands for the electric output), rather than for actual SMR designs. However, each of such “model” SMR reflects the characteristics of specific SMR designs. The PWR-X and the basic designs were selected:

— To cover the whole range of unit electrical outputs, from 8 to 335 MWe.

— To cover a variety of possible plant configurations, including single module plants, twin — units and pairs of twin-units, multi-module plants, and barge-mounted and land-based plants.

— To represent the ongoing developments in several countries.

— It is assumed that these “model” PWR-X SMRs have reached industrial maturity and thus no path to development is analysed in this chapter.

• Reference NPPs with large reactors were selected based on the following criteria:

— Availability of the necessary economic data (overnight capital costs, O&M and fuel costs) in the OECD report Projected Costs of Electricity Generation, 2010 Edition [7.1] used as reference in the current study.

— Matching the country of origin of a particular SMR corresponding to the PWR-X for which the independent LUEC estimate was obtained.

To cater for possible uncertainties associated with the method used for LUEC estimation, two reference NPPs with different large reactors were attributed to the same PWR-X in one case. The selection of particular NPPs with large reactors for those cases is explained in the following paragraphs.

Table 7.1 presents the SMRs that have been analysed in this chapter (PWR-X) and the reference plant used as a basis for the LUEC estimation. As was already mentioned, reference NPPs with large reactors were typically selected to come from the same country of origin as the corresponding SMRs used as a basis for a PWR-X. In the case of the PWR-90, based on Korean SMART, two different NPPs with large reactors were considered, both of Korean origin. Comparison of the PWR-90(1) and (2) then makes it possible to evaluate the uncertainty related to the selection of a particular large reference NPP for scaling.

For PWR-125 (based on the mPower project) and for PWR-335 (based on the IRIS project), the choice of reference NPP with a large reactor was the Advanced Gen. III+ from [7.1]. Such a choice reflects the fact that the designers of the mPower are currently concentrating on the deployment of their design in the United States [7.3].

For PWR-8,-35,-302 corresponding to the Russian marine derivative reactors, the reference NPP with a large reactor was the VVER-1150 from [7.1].

Formula (6.1) for LUEC given in Section 6.1 was used in the evaluations. For the purposes of the present chapter and following the discussion in section 6.3, the sums of the O&M and fuel costs for land-based SMRs were taken equal to the corresponding sums for NPPs with the reference large

reactors. For barge-mounted plants, the corresponding sums were multiplied by a factor of 1.5 reflecting the assumption of a higher O&M costs owing to the need of periodical factory repairs of a barge. Further specific assumptions made in the evaluation of particular LUEC components are highlighted in the following sections.

Table 7.1. SMRs and plant configurations for which independent LUEC estimates were obtained and the overnight costs (OVC) for single-SMR plants PWR-8 PWR-35 PWR-90(1) PWR-90(2) Electric output (net), MWe 7.9 35 90 90 Construction period/ Plant lifetime, years 4/50 4/40 3/60 3/60 Availability, % 80 85 90 90 SMR of relevance from Table 4.14 ABV KLT-40S SMART SMART Large reactor used a basis for scaling [7.1] VVER-1150 VVER-1150 APR-1400 OPR-1000 Plant configurations considered for SMR Twin-unit barge-mounted plant Twin-unit barge-mounted plant Single unit land-based plant Single unit land-based plant Electric output for large reactor, MWe 1 070 1 070 1 343 954 OVC for large reactor, USD/kWe 2 933 2 933 1 556 1 876 OVC for SMR, scaled with n=0.51, USD per kWe 32 500 15 700 5 850 5 970 Design simplification factor 0.85 OVC for single-SMR plant, USD oer kWe 27 600 13 300 4 970 5 070 Total OVC for single-SMR plant, USD million 2×218 2×465 447 456

	PWR-125	PWR-302	PWR-335
	Electric output (net), MWe		125	302	335
Construction period/ Plant lifetime, years	3/60	4/60	3/60
	Availability, %		90	92	96
SMR of relevance from Table 4.14	mPower	VBER-300	IRIS
Large reactor used a basis for scaling [7.1]		Advanced Gen III+	VVER-1150	Advanced Gen III+
Plant configurations considered for SMR	five module plant	— Twin-unit barge-mounted plant; — Twin-unit land-based plant	— Two twin-unit land-based plant
	Electric output for large reactor, MWe		1 350	1 070	1 350
OVC for large reactor, USD/kWe	3 382	2 933	3 382
	OVC for SMR, scaled with n=0.51, USD per kWe		10 853	5 450	6 695
Design simplification factor	0.85
	OVC for single-SMR plant, USD oer kWe		9 225	4 630	5 690
Total OVC for single-SMR plant, USD million	1 153	2×1 398	1 906

Investment cost for a single SMR PWR-X has been estimated applying the methodology described in Section 6.2 and summarised in Figure 7.1.

Following the discussion in Section 6.2, the overnight cost of a single SMR was obtained using a scaling law with n=0.51;

As a second step, the overnight costs for the plant configurations (defined in Table 7.1) were estimated. These estimates used different factors accounting for possible cost reductions in a twin — unit, a multi-module and a barge-mounted plant. The details of the calculation are given in Appendix 3(Table A3.4). As many of the factors are specified as ranges, the resulting overnight capital costs most often also appear as ranges rather than single values. Those results are graphically illustrated in Figure 7.2.

Figure 7.2. Overnight costs for various NPP configurations with SMRs (data from Table A3.4) USD per kWe

Following the calculation of overnight costs for the various SMR plant configurations, the corresponding investment costs were estimated. The investments were assumed to be spread uniformly over the whole construction period and were evaluated separately at a 5% and at a 10 % discount rate. Estimates of the investment costs for the SMR plant configurations in Table 7.1 are given in Table 7.2. This table provides both the specific investment costs in USD per kWe and the total investment in USD.

From Table 7.2 it can be seen that, while the specific investment costs (per kWe) are in some cases quite high, the total investments in USD are relatively small for a small reactor. For single-SMR plants with the electric output below 125 MWe the total investments are well below USD 1 billion (see Table 7.1).

PWR-302

twin-unit land — „С 302×2=604 3 750-4170 4 4 250-4 720 2.57-2.85 4 790-5 320 2.89-3.22

based

670×2=1 340 4 610-5 122 3 5 086-5 651 6.8-7.57 5 594-6 216 7.5-8.3

In Figure 7.3, the overnight costs for the various plant configurations with SMRs are compared with the overnight costs for NPPs with large reactors currently available in the world. It could be seen that the projects with several SMR units, yielding significant overall amounts of electric power, seem to have overnight costs comparable to those for some NPPs with large reactors in Europe and in North America. In Asia, the construction of NPPs with large reactors requires significantly less capital than in Europe and North America, and all of the plant configurations with SMRs would be more expensive to build (except some very small, including the one developed in the region — 1^90 MWe, the Republic of Korea).